Slipping off your shoes in a security line is practically a law of air travel. But anyone who’s ever been left barefoot on the cold airport floor has likely wondered: Should I be wearing socks?

The short answer: Probably. "Just about every floor surface—at shopping centers, gyms, airports, and other places—is coated in bacteria like E. coli and Staph as well as other pathogens," says Kathryn H. Jacobsen, Ph.D., a professor of epidemiology and global health at George Mason University. If that bacteria seeps into your skin, you're at risk for an infection.

It sounds scary—and it’s better to be safe than sorry—but keeping your feet covered is mostly precautionary. Jacobsen says that for most of us, the risk of contracting an infection from going sock-less at security is pretty low. In part, that’s because security lines are well-ventilated and have dry floors, so you’re unlikely to pick up either foot fungi (think: athlete’s foot) or plantar warts—both of which tend to come from damp environments, like locker rooms with showers.

There are exceptions. Anyone with a weakened immune system (for example, if you suffer from diabetes-related foot problems) or with cuts on their feet could more easily have pathogens enter the body.